Disc-shaped recording medium, method and apparatus for manufacturing same and data recording method

ABSTRACT

An optical disc ( 200 ) according to the present invention has a recording area divided into 28 zones of from a zone Z 0  to a zone Z 27 . In a given zone, the number of waves of a wobble is set so as to be equal, that is, the number of waves of the ADIP carrier is set so as to be equal, between optional two neighboring turns of the track or between optional two neighboring tracks. This achieves inphase-outphase matching on an average, for decreasing a WPP signal, so that such an optical disc may be provided in which no low frequency components are superposed on push-pull signals, even though the optical disc is of such a type in which the track pitch is narrower than 1.6 μm, such as 1.25 μm, or in which a mark is detected by DWDD from a groove, as in the case of the next generation MD 2.

TECHNICAL FIELD

This invention relates to a disc-shaped recording medium, having a trackwobbled in keeping with the address information, a manufacturing methodand apparatus therefor, and a data recording method.

This application claims priority of Japanese Patent Application No.2002-098044, filed in Japan on Mar. 29, 2002, the entirety of which isincorporated by reference herein.

BACKGROUND ART

An optical disc, approximately 64 mm in diameter, having a recordingcapacity capable of recording music sound signals for 74 minutes orlonger, is currently in use. This small-sized optical disc, termed aMini-Disc (registered trademark), is classified into a replay-only disc,having data recorded as pits, and a recording and/or reproducing disc,having data recorded by a magneto-optical recording (MO) system andwhich may thus also be reproducible. The following description isdirected to a small-sized recording and/or reproducing disc, referred tobelow as an optical disc. With this optical disc, the track pitch, therecording wavelength of the recording laser light or the NA of theobjective lens have come to be ameliorated in order to increase disc'srecording capacity.

In the following explanation, an optical disc of an initial stage, inwhich groove recording is carried out with the track pitch of 1.6 μm, istermed the first generation MD. The physical format of this firstgeneration MD is prescribed as follows: The track pitch is 1.6 μm andthe bit length is 0.59 μm/bit. The laser wavelength λ is set to λ=780 nmand the numerical aperture of the optical head NA is set to NA=0.45. Therecording system employed is the groove recording system in which agroove (i.e. a groove formed on the disc surface) is used as a track forrecording and/or reproduction. The address system employed is a systememploying the wobbled groove in which a single-spiral groove is formedon a disc surface and in which a wobble as the address information isformed on both sides of this groove. Meanwhile, in the presentspecification, the absolute address recorded by the wobbling is termedan ADIP (Address in Pre-Groove).

In the conventional Mini-Disc, an EFM (8 to 14 modulation) system isemployed as the recording data modulating system. As the errorcorrection system, ACIRC (Advanced Cross Interleave Reed-Solomon Code)is used. For data interleaving, a convolution type data interleaving isused. In this manner, data redundancy amounts to 46.3%.

In the first generation MD, the data detection system is a bit-by-bitsystem, while the disc driving system used is the CLV (Constant LinearVelocity) system. The linear velocity of the CLV system is 1.2 m/sec.

The standard data rate during recording and/or reproduction is 133kB/sec, while the recording capacity is 164 MB (140 MB for MD-DATA). Theminimum data re-write unit (cluster) is constructed by 36 sectorscomposed of 32 main sectors and four link sectors.

In these days, the next-generation MD, having a recording capacityfurther improved over the first generation MD, is being developed. Suchan MD in which the medium is unchanged from the conventional medium(disc orb cartridge), and in which the modulation system or the logicalstructure is changed to provide for a double-density user area toincrease the recording capacity to for example 300 MB is nowcontemplated. This MD is referred to below as the next-generation MDI.The physical parameters of the recording medium are the same, the trackpitch is 1.6 μm, the laser light wavelength λ is such that λ=780 nm andthe numerical aperture of the optical head NA is such that NA=0.45. Therecording system used is the groove recording system. The address systemused is the ADIP. Thus, the structure of the optical system, ADIPaddress readout system and the servo processing in the disc drivingdevice are similar to those of the conventional mini-disc.

An MD further improved in the recording capacity over thenext-generation MD1 (next-generation MD2) is also being developed, inwhich the track pitch is reduced to 1.25 μm and in which a recordingmark is detected by DWDD (Domain Wall Displacement Detection) from theaforementioned groove.

Meanwhile, if it is attempted to rotationally drive and therebyreproduce the next-generation MD2, in which the recording capacity hasbeen increased by exploiting the DWDD, with the CLV (Constant LinearVelocity) in the same way as in reproducing the next generation MD1, theadverse effect ascribable to tracking offset becomes significant becausethe reproducing spot is larger than the mark. Specifically, if even thesmallest tracking offset is produced, the result is that a mark from aneighboring track is also picked up, because of the narrow track pitch,thus significantly lowering the readout characteristics.

That is, with an optical disc, such as the next-generation MD2, whichhas the track pitch further narrowed and which is reproduced withultra-high resolution by DWDD, it is necessary to cope with detrackingextremely rigorously.

The next generation MD2 is also of the ADIP addressing system and, ifthe carrier frequency of the track is offset every track period by CLV,as shown in FIG. 1, the ADIP phase is also offset. With the nextgeneration MD2, as in other MDs, the push-pull signal PP, detected withone spot, is detected and used as a tracking error signal. However, lowfrequency components of a few Hz appears as a beat component in thepush-pull signal, as shown in FIG. 2. This push-pull signal is increasedas a wobble push-pull signal WPP to the extent shown in FIG. 3. With thesignal of the magnitude as large as that shown in FIG. 3, detracking isunavoidably produced in the next generation MD2.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a disc-shapedrecording medium in which no low frequency components are superposed onthe push-pull signal even in the above-described next generation MD2 inwhich the track pitch is narrower than that of the first generation MDand is 1.25 μm and in which the mark is detected from the groove byDWDD.

It is another object of the present invention to provide a method andapparatus for manufacturing a disc-shaped recording medium.

It is yet another object of the present invention to provide a methodfor recording data on a disc-shaped recording medium.

For accomplishing these objects, the present invention provides adisc-shaped recording medium wherein a signal recording surface of thedisc-shaped recording medium is split into a plurality of zones andwherein a track(s) is formed spirally or concentrically such that, ineach zone, the number of waves of a wobble is the same from one turn ofthe track(s) to the next.

The present invention also provides a method for manufacturing adisc-shaped recording medium wherein the speed of rotation of thedisc-shaped recording medium, having a signal recording surface dividedinto a plurality of zones along the radial direction, is changed fromone zone to the next, and wherein the wobble frequency is controlled sothat, in each zone, the number of waves of the wobble of neighboringturns of the track(s) is the same from one turn of the track(s) to thenext. The present invention also provides an apparatus for manufacturinga disc-shaped recording medium comprising disc rotating means forrotationally driving a disc-shaped recording medium having a signalrecording surface divided into a plurality of zones along the radialdirection, driving means for driving the disc rotating means, a phasesynchronization circuit for generating optional clocks, and controllingmeans for controlling the driving means so that the speed of rotation ofthe disc-shaped recording medium is changed from one zone of thedisc-shaped recording medium to the next and for controlling the phasesynchronization circuit so that, in each zone, the number of waves ofthe wobble of optional two neighboring turns of the track(s) is equalfrom one zone of the disc-shaped recording medium to the next.

The present invention also provides a data recording method in which, inrecording data on a disc-shaped recording medium, having a signalrecording surface divided into a plurality of zones along a radialdirection, the recording medium including a track(s) formed spirally orconcentrically so that, in each zone, the number of waves of a wobble isequal from one turn of the track(s) to the next, recording of the datais inhibited in the vicinity of a boundary between neighboring zones.

Other objects, features and advantages of the present invention willbecome more apparent from reading the embodiments of the presentinvention as shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the manner of progressive track carrier frequencydeviation.

FIG. 2 depicts low frequency components (beat components) of a few Hzsuperposed on a push-pull signal.

FIG. 3 depicts a waveform of a WPP signal.

FIG. 4 depicts zone splitting of an optical disc.

FIG. 5 shows the manner in which the number of waves of the wobble ismade coincident in a given zone and non-coincident from zone to zone.

FIG. 6 shows the manner in which the number of waves is made equal fromone turn of a track to the next or from one track to the next.

FIG. 7 is a waveform diagram of a WPP signal.

FIG. 8 shows a track structure in the vicinity of a zone-to-zonejunction.

FIG. 9 illustrates that the density ratio in each zone is substantiallyuniform.

FIG. 10 shows the relationship between the number of zones, densityratio and the zone-to-zone speed offset.

FIG. 11 is a block diagram of a formatter used in the process ofmanufacturing the next generation MD2 by ZCAV.

FIG. 12 shows a structure for calculating the frequency in the PLL ofthe formatter.

FIG. 13 shows the former half of a first specified embodiment of thezone layout formed by the constant in-zone density ratio system.

FIG. 14 shows the latter half of the first specified embodiment of thezone layout formed by the constant in-zone density ratio system.

FIG. 15 shows the former half of a second specified embodiment of thezone layout formed by the constant in-zone density ratio system.

FIG. 16 shows the latter half of the second specified embodiment of thezone layout formed by the constant in-zone density ratio system.

FIG. 17 shows a data format on the disc in accordance with the zonelayout shown in FIGS. 15 and 16.

FIG. 18 is a block diagram showing an optical disc recording and/orreproducing apparatus for recording and/or reproducing informationsignals for the next generation MD2 of the ZCAV system.

FIG. 19 is a block diagram showing the structure of an optical discrecording and/or reproducing apparatus for recording and/or reproducingthe Mini-Disc (first generation MD), next generation MD1 and the nextgeneration MD2.

FIG. 20 shows the data block structure including BIS of the nextgeneration MD1 and the next generation MD2.

FIG. 21 shows the ECC format for a data block of the next generation MD1and the next generation MD2.

FIG. 22 schematically shows an illustrative area structure on a discsurface of the next generation MD2.

FIG. 23 illustrates the relationship between the ADIP sector structureand the data block of the next generation MD1 and the next generationMD2.

FIGS. 24A and 24B show a data structure of the ADIP.

FIG. 25 illustrates the processing of embedding a disc control signal inthe ADIP signal of the next generation MD2.

FIG. 26 is a block diagram showing the structure of a disc drive device.

FIG. 27 is a flowchart showing the processing in a system controller ina disc drive device in case a request for reading out a given FAT sectoris made from a PC.

FIG. 28 is a flowchart showing the processing in a system controller ina disc drive device in case a request for reading out a given FAT sectoris made from the PC.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings, preferred embodiments of the presentinvention are hereinafter explained.

FIG. 4 shows a zoned format of an optical disc 200 such as the nextgeneration MD2. In this optical disc 200, the surface of the opticaldisc is divided into 28 zones of from Z₀ to Z₂₇. In a given zone, thenumber of waves (phase) of a given track is made coincident with that ofa neighboring track. For example, in FIG. 5, showing the zones Z₁ and Z₂to an enlarged scale, the number of waves (phase) of the wobble is madecoincident, in the zone Z₁, as indicated by an encircled area A₁. In thezone Z₂, the number of waves (phase) of the wobble is again madecoincident, as indicated by an encircled area A₁. FIG. 6 shows thewobble in the area A₁ as taken out and that in an area A₂ as taken out.The numbers of waves in these areas coincide with each other. This istantamount to equating the number of waves of the ADIP carrier. Thisenables inphase-outphase matching on an average, such that the WPPsignal shown in FIG. 7 is of a magnitude smaller than that shown in FIG.3. Meanwhile, the number of waves (phase) of the wobble of the zone Z₁need not be coincident with that of the zone Z₂ neighboring to the zoneZ₁, as indicated by an encircled area A₃.

In the same zone of the optical disc 200, the reproduction is by CAV.However, for the recording and/or reproducing apparatus, thereproduction appears to be the same as that when the spindle motor iscontrolled as conventionally to rotationally drive the disc by CLV. Thisdisc driving system is termed the ZCAV system.

The next generation MD2 is now explained. The next generation MD2 is arecording medium which applies the high density recording technique,such as the DWDD (Domain Wall Displacement Detection), and differs fromthe above-described conventional Mini-Disc or the next generation MD1 asto the physical format. The next generation MD2 has a track pitch of1.25 μm and a bit length of 0.16 μm/bit, and is increased in densityalong the line direction.

For compatibility with the conventional Mini-Disc and with the nextgeneration MD1, the standard for the optical system, readout system orthe servo processing are in keeping with the conventional standard, suchthat the laser wavelength λ=780 nm and the numerical aperture NA=0.45.The recording system is the grooved recording system, while theaddressing system is the system exploiting the ADIP. As for the outershape of the casing, the standard for the conventional Mini-Disc and thenext generation MD1 applies.

However, in case the track pitch narrower than that of the conventionalpractice and the line density (bit length) are to be read out using anoptical system equivalent to that of the conventional Mini-Disc and thenext generation MD1, it is necessary to resolve constraint conditions ine.g. detracking margin, crosstalk from the land or the groove,defocusing, or CT signals. Consequently, the next generation MD2 isfeatured by changes made in groove depth, inclination or width.Specifically, the depth, inclination and width of the groove are set to160 to 180 nm, 60° to 70° and to 600 to 800 nm, respectively.

The next generation MD2 employs, as a recording data modulation system,the RLL (1-7) PP modulation system (RLL; Run Length Limited, PP; Paritypreserve/Prohibit rmtr (repeated minimum transition runlength)), suitedto high density recording, while employing, as the error correctionsystem, an RS-LDC (Reed Solomon-Long Distance Code) system with BIS(Burst Indicator Subcode) having a higher correction capability.Deinterleaving is a block completion type. By this, data redundancy is20.50%. The data detection system is the viterbi decoding system by PR(1, −1) ML. The cluster, as a minimum data rewrite unit, is formed by 16sectors, 64 kB.

The disc driving system used in the ZCAV system of the presentinvention, with the linear velocity being 2.0 m/sec. The standard datarate in recording and/or reproduction is 9.8 MB/sec. Thus, with the nextgeneration MD2, the total recording capacity can be 1 GB by employingthe DWDD system and this driving system.

FIG. 8 shows a track structure of in the vicinity of a junction betweenneighboring zones. Two dummy tracks are inserted between the trailingtrack TZ₀L of the zone Z₀ and the leading track TZ₁S of the zone Z₁.These dummy tracks are a dummy track TZ₀D of a carrier frequencyequivalent to the carrier frequency of the zone Z₀ and a dummy trackTZ₁D of a carrier frequency equivalent to the carrier frequency of thezone Z₁. The innermost rim and the outermost rim of at least two tracksis composed of two clusters and four clusters, respectively. Thejunctions are discontinuous and are not used for recording and/orreproduction. Although the ADER holds in one junction sector in an areaA in FIG. 8, this is a dummy cluster and hence is not problematical. Thejunctions are arrayed on the same radial line indicated by an arrow B.

A specified example of zone allocation is hereinafter explained. Here, aconstant in-zone density ratio system is explained. In this system, theratio between the inner radius and the outer radius is adapted to beconstant. For example, assume that the radius up to the inner rim andthat up to the outer rim of the zone Z₁ are r1 and r2, respectively,while the radius up to the inner rim and that up to the outer rim of thezone Z₂ are r2 and r3, respectively, as shown in FIG. 9. Also assumethat the radius up to the inner rim and that up to the outer rim of thezone Z₂₂ are r22 and r23, respectively. The zone splitting is made sothat the equation r2/r1=r3/r2=. . . r23/r22 holds, so that the in-zonedensity ratio system is constant. With this in-zone density ratiosystem, priority is on RF characteristics.

If the next generation MD2 has a track pitch of 1.25 μm and the maximumlinear density is 0.16 μm/bit, and the number of zones is 27, the numberof tracks/zone is 268 to 576, while the number of clusters/zone is 297to 975. The line density is 0.1602 to 0.1667 μm/bit. As a result, therecording capacity is 1.025 G (109). With the number of zones of 27, thezone-to-zone speed offset is 2.54%. The number of clusters/zone is anumber excluding four cluster breakages and four cluster interchanges.The recording capacity is a value excluding the interchange recordingunit. The recording capacity is a value excluding the exchange recordingunit.

FIG. 10 shows the relationship between the number of zones, recordingcapacity and the density ratio or the zone-to-zone speed offset. It maybe seen that the number of zones of from 23 to 28 is an optimum range.

With this in-zone density ratio system, the zone-to-zone speed offsetwhen an optical head traverses a boundary between two neighboring zonesis of a small value not larger than 3%, so that the number ofrevolutions of the spindle motor may be changed smoothly. That is, in agiven zone, the spindle motor is being run in rotation at a constantvelocity. A rotationally driving controller does not see this in such amanner that it is rotationally driving the disc at CAV in a given zone,but rather see this in such a manner that the rotationally drivingcontroller is rotationally driving the disc in an attempt to make thecarrier frequency of the ADIP constant.

FIG. 11 shows the structure of a formatter 300 used in a process ofmanufacturing the next generation MD2 rotationally driven at ZCAV. Inproducing a disc, usually a disc is rotated at CAV, and a wobble isformed as the frequency is changed. To this end, the formatter 300includes two circuits of the PLL, each for a zone, that is a PLL 303 andPLL 304, and clocks for zone cutting are changed, without producinginterruptions, by switching between these PLLs 303 and 304.

When a disc is CAV—cut at 900 rpm, the PLL 301 generates, from masterclocks (33.8688 MHz), a frequency of 15.75 kHz for synchronizing the FGof the spindle motor, to route the so produced frequency to a spindledriver 302. This spindle driver 302 sends this frequency of 15.75 kHz toa cutting apparatus.

The PLL 303 and the PLL 304 are used for generating an ADIP wobblefrequency from the master clock (33.8688 MHz).

A cluster counter zone switching M/N table 306 has stored thereinM/N=36/35˜67/35. In order to create the ADIP wobble frequency betweenneighboring zones, without interruptions, M2/N and M1/N are supplied tothe PLL 304 and to the PLL 303, respectively.

A changeover switch 305 switches between clocks from the PLL 303 andthose from the PLL 304, under control by the cluster counter zoneswitching M/N table 306.

An address counter 307 counts up an address of an inner zone. A BCHencoder 308 appends ECC to a count output. A bi-phase encoder 309bi-phase encodes an ECC-appended output. An FM converter 310frequency-modulates the bi-phase output into a sine wave which is routedto a driver 311. This driver 311 routes the sine wave signal to a wobblecutting apparatus.

An optical head of the wobble cutting apparatus illuminates a laserlight beam on a master disc, having its surface coated with aphotoresist, as the laser light beam is wobbled in keeping with asupplied FM signal. The master disc is run in rotation by a spindlemotor at this time at CAV, from zone to zone, and clocks are changedover by the PLL 303 and PLL 304, with a zone-to-zone speed offset whenthe optical head traverses a boundary between two neighboring zones,which speed offset is small and is 3% or less. The surface of the masterdisc is sensitized and developed on the to the shape of wobbled groovescorresponding to the address information. The wobbling groove is formedon the developed master disc and a land is formed between neighboringgrooves. A stamper is manufactured from this master disc and, using thisstamper, a large number of optical discs, as replica discs, as the nextgeneration MD2, are produced. The above is a specified example of themethod and the apparatus for manufacturing the optical disc of thepresent invention.

FIG. 12 shows an arrangement for calculating the frequency by the PLL301, PLL 303 and the PLL 304. The arrangement allows for clocksynchronization once each complete revolution of the master disc. Thatis, if the format is such that switching occurs at the same position asthis clock synchronization position, zone switching free from phasedeviation may be achieved. To this-end, the PLL 301 multiplies 33.8688MHz by 25/105 and further multiplies the resulting frequency by 1/512with the resolution 3=resolution 1×resolution 2 (as will be explainedlater) to yield 15.75 kHz which is supplied to a cutting device.

The PLL 303 multiplies 33.8688 MHz by M1/N. The driver condition in thiscase is to set M/N to unity (1), to set the phase comparison frequencyto not less than 1 MHz and to suppress the master clocks to 50 MHz orless. In the zone Z₀, M/N being set to unity denotes M=N, such that, incase the CLV mode is used, the PLL may be dispensed with. The phasecomparison frequency is set to 1 MHz or higher because the phase isdetermined from channel clocks and hence the clocks may be distinct frommaster clocks.

The PLL 304 multiplies 33.8688 MHz by M2/N, provided that the PTOCportion represented by ADIPU is multiplied by 16/15 so that one clusteris comprised in one complete revolution of the master disc.

With the resolution 1 in the changeover switch 305, the clocks changedover are multiplied by 1/16 to generate system clocks of 2.1168 MHz to4.05216 MHz. These clocks are then divided by the number of carriers andmultiplied by 1/32 with the resolution 2 to generate 15 Hz which is thefrequency for one complete revolution. The resolution 2 is theresolution for wobble generation. In case of 1/64, the 1/16 frequencydivision of the preceding stage is changed to 1/8. This doubles thefrequency of the system clocks.

Meanwhile, the arrangement by PLL is used for such a case that the diveis used at CAV in future. Although the next generation MD2 is adapted tobe usable for CLV as well for assuring compatibility to the firstgeneration MD and for the next generation MD1, the next generation MD2is adapted for being used conveniently for an apparatus intrinsicallyrun in rotation at CAV.

For satisfying the condition of the arrangement shown in FIG. 12, thefollowing conditions need to be met from zone to zone:Condition 1: M/N×(1/(number of carriers per track))=1/1050

It is possible to generate clocks by clock synchronization being enabledevery period and by provision of a PLL capable of M/N multiplication.This means that a simpler arrangement may be used in case the masterdisc is run in rotation by a drive at CAV to change over the clocks,instead of simply using the arrangement as a formatter. The arrangementmay be further improved in flexibility by adding a PLL of B/A in aportion corresponding to 1/1050 on the right side of the above equation.Condition 2: (number of carriers per track×number of tracks perzone)/(number of carriers per recording unit)=integer:

That is, the total number of carriers per zone is divisible by therecording unit, as the unit of recording and/or reproduction, wherebyswitching may be made in continuation to the next zone. In the format ofthe present specified example, the number of carriers per recording unitis 4704.

FIGS. 13 and 14 shows a first specified example of a zone layout formedby the in-zone density ratio system, while FIGS. 15 and 16 show a secondspecified example thereof. The number of carriers of the zone Z⁻¹ is4704. The number of carriers per complete revolution is designed to becompletely divisible by one cluster in one complete revolution. Thereason is that a fixed pattern is written in the zone Z⁻¹ and hencecorrection may be made at any optional time to the correct number ofcarriers by reverting to this zone Z⁻¹ even though the disc is skewed asa result of interference.

Meanwhile, the reason that the density ratio when the optical head isastride the boundary between neighboring zones is set to 3% or less isthat the PLL pull-in range is ±4% and that, if the density ratio is lessthan this, the arrangement may be moved as the PLLs are changed overcontinuously.

FIG. 17 shows a data format on a disc in accordance with the zone layoutshown in FIGS. 15 and 16. In an area from the inner rim up to a radiusof 15.7 mm, a unique ID is recorded by MO and, in an area from this areaup to a radius of 16.0 mm, there is recorded a lead-in/PTOP (zone Z⁻¹).BRU is a buffer recording unit. LPCA is a laser power calibration area.In DDT (Disc Description Track) & Secure Area, there are stated theinformation on the disc sort, design disc parameters or the informationrequired for security management. Next to this information, there arerecorded zones Z₀, Z₁, . . . , zone Z₂₆, accompanied by spare recordingunits (SPUs) and BRUs. Between the last zone Z₂₇ and the lead-out areinserted the SRU and LPCA.

Referring to FIG. 18, an optical disc recording and/or reproducingapparatus for recording and/or reproducing information signals for theabove-described next generation MD2 of the ZCAV system, is hereinafterexplained.

This optical disc recording and/or reproducing apparatus includes anarrangement for executing the RLL (1-7) PP modulation RS-LDC encoding,for recording the next generation MD2, while also including anarrangement for executing the RLL (1-7) demodulation RS-LDC decodingbased on data detection employing PR (1, −1) ML and viterbi decoding forreproducing the next generation MD2.

This optical disc recording and/or reproducing apparatus rotationallydrives the next generation MD2 (200), loaded in position, by a spindlemotor 401, in accordance with the aforementioned ZCVA system. Inrecording and/or reproduction, laser light is illuminated from anoptical head 402 to the next generation MD2 (200).

The optical head 402 outputs high level laser light for heating therecording track to the Curie temperature, at the time of recording,while outputting the laser light of a lower level for detecting datafrom the reflected light by the magnetic Kerr effect, at the time ofreproduction. To this end, the optical head 402 has loaded thereon anoptical system, such as a laser diode, as laser outputting means, apolarizing beam splitter or an objective lens, and a detector fordetecting the reflected light. The objective lens, provided to theoptical head 402, is held for displacement by for example a biaxialactuator along the radius of the disc and in a direction towards andaway from the disc.

A magnetic head 403 is arranged on the opposite side to the optical head402 with respect to the next generation MD2. The magnetic head 403applies a magnetic field, modulated by recording data, to the nextgeneration MD2. There are also provided a sled motor and a sledmechanism, not shown, for causing movement of the optical head 402 inits entirety and the magnetic head 403 along the radius of the disc. Inthis magneto-optical recording and/or reproducing apparatus, there arealso provided a recording processing system, a reproducing processingsystem and a servo system, in addition to the recording and/orreproducing head system by the magnetic head 403 and the disc rotationaldriving system by the spindle motor 401. As a recording processingsystem, there is provided a circuit unit responsible for RLL (1-7) PPmodulation and RS-LDC encoding at the time of recording on the nextgeneration MD2.

As a reproducing processing system, there are provided a unit fordemodulation associated with the RLL (1-7) PP modulation (RLL (1-7)demodulation based on data detection employing PR (1, −1) ML and viterbidecoding at the time of reproducing the next generation MD2) and a unitfor executing RS-LDC decoding.

The information detected as reflected light of the laser lightilluminated by the optical head 402 on the next generation MD2 (opticalcurrent obtained on detecting the reflected laser light by thephotodetector) is sent to an RF amplifier 404. The RF amplifier 404performs current to voltage conversion, amplification and matrixcalculations on the detected information and extracts the replay RFsignals, tracking error signals TE, focusing error signals FE or thegroove information (ADIP information recorded by track wobbling on thenext generation MD2) as the replay information.

At the time of reproducing the next generation MD2, the replay RFsignals, obtained by the RF amplifier, are processed by an RLL (1-7) PPdemodulating unit 409 and an RS-LDC decoder 410, via an A/D convertingcircuit 405, an equalizer 406, a PLL circuit 407 and a PRML circuit 408.In reproducing the replay RLL signal, replay data, as a RLL (1-7)codestring, is obtained by data detection employing PR (1, −1) ML andviterbi decoding, in a RLL (1-7) PP demodulating unit 409 and RLL (1-7)demodulating processing is carried out on this RLL (1-7) codestring.Error correction and deinterleaving processing are then carried out inan RS-LDC decoder 410. The resulting demodulated data is then output toa data buffer 415 as replay data from the next generation MD2.

The tracking error signals TE and the focusing error signals FE, outputfrom the RF amplifier 404, are routed to a servo circuit 411, while thegroove information is supplied to an ADIP decoder 413.

The ADIP decoder 413 limits the bandwidth of the groove information by aband-pass filter to extract wobble components, and subsequently performsfrequency demodulation and bi-phase demodulation to extract the ADIPaddress. The demodulated ADIP address, as the absolute addressinformation on the disc, is supplied to a system controller 414, asbeing the next generation MD2 address.

The system controller 414 executes preset control processing, based onthe ADIP address. The groove information is returned to the servocircuit 411 for spindle servo control.

Based on an error signal, obtained on integrating a phase error of thereplay clocks (PLL based clocks at the time of decoding) with respect tothe groove information, the servo circuit 411 generates a spindle errorsignal for ZCAV servo control.

The servo circuit 411 generates a variety of servo control signals(tracking control signals, focusing control signals, sled controlsignals or spindle control signals) based on the spindle error signals,tracking error signals and focusing error signals, supplied from the RFamplifier 404, a tracking jump command or an access command from thesystem controller 414, to output the so generated control signals to amotor drive 412. Specifically, the servo circuit 411 performs necessaryprocessing, such as phase compensation processing, gain processing ortarget vale setting, on servo error signals or commands, to generate avariety of servo control signals.

The motor drive 412 generates preset servo driving signals, based onservo control signals supplied from the servo circuit 411. The servodriving signals prove biaxial driving signals (two signals of focusingsignals and tracking signals) actuating a biaxial mechanism, sled motordriving signals, actuating the sled mechanism, and spindle motor drivingsignals, actuating the spindle motor 401. By these servo drivingsignals, focusing control and tracking control are performed on the nextgeneration MD2, while ZCAV control is performed on the spindle motor401.

When the recording operation is performed on the next generation MD2,high density data are supplied from a memory transfer controller, notshown, or usual compressed ATRAC data are supplied from an audioprocessing unit.

In recording on the next generation MD2, an RS-LDC encoder 416 and anRLL (1-7) PP modulating unit 417 are in operation. In this case, thehigh density data are interleaved and added by an error correction codeof the RS-LDC system in the RS-LDC encoder 416 and RLL (1-7) modulatedby the RLL (1-7) PP modulating unit 417.

The recording data, modulated into an RLL (1-7) codestring, is suppliedto a magnetic head driver 418 to cause the magnetic head 403 to apply amagnetic field corresponding to the modulated data to the nextgeneration MD2 to record the data.

A laser driver/APC 419 causes a laser diode to perform a laser lightemitting operation during reproduction and during recording, asdescribed above, and also performs so-called APC (Automatic Laser PowerControl). Specifically, there is provided a detector for laser powermonitoring within the optical head 402. These monitor signals are fedback to the laser driver/APC 419. This laser driver/APC 419 compares thecurrent laser power, obtained as a monitor signal, to a pre-set laserpower, and causes an error therebetween to be reflected in a laserdriving signal to manage control such that the laser power output fromthe laser diode will be stabilized at a setting value. It is noted thatthe value of the laser power, in terms of the replay laser power and therecording laser power, are set by the system controller 414 in aninternal register of the laser driver/APC 419.

The system controller 414 controls the various components so thatabove-described various operations (accessing, various servo operations,data write and data readout operations) are executed.

The next generation MD2, in which zone allocation has been made inaccordance with the in-zone density ratio system, may be run in rotationby the optical disc recording and/or reproducing apparatus in accordancewith the ZCAV system.

Thus, the number of waves of the ADIP carrier is uniformed in a givenzone to suppress the low frequency beat components from the ADIP wobbleto a smallest possible value, while it appears to the drive as if thedisc is being rotated in accordance with the CLV system.

Thus, even with the magneto-optical recording and/or reproducingapparatus of the type intrinsically actuating the first generation MD orthe next generation MD1 by the CLV system, it is possible torotationally drive the next generation MD2 to record/reproduce theinformation.

FIG. 19 shows an arrangement of an optical disc recording and/orreproducing apparatus 11 for recording and/or reproducing theconventional Mini-Disc (first generation MD), next generation MD1 andthe next generation MD2. This optical disc recording and/or reproducingapparatus 11 discriminates the next generation MD1 and the nextgeneration MD2 from each other. There are occasions where the opticaldisc recording and/or reproducing apparatus 11 discriminates firstgeneration MD and the second generation MD2 from each other.

The optical disc recording and/or reproducing apparatus 11 is featuredby including, for recording and/or reproducing the conventionalMini-Disc, next generation MD1 and the next generation MD2, anarrangement for executing EFM modulation and ACIRC encoding forrecording the conventional Mini-Disc and an arrangement for executingthe RLL (1-7) PP modulation and RS-LDC encoding for recording the nextgeneration MD1 and the next generation MD2. The optical disc recordingand/or reproducing apparatus 11 is also featured by including, as areplay processing system, an arrangement for executing EFM demodulationand ACIRC decoding for reproducing the conventional Mini-Disc and anarrangement for executing RLL (1-7) demodulation RS-LDC decoding basedon data detection employing PR (1, 2, 1) ML, PR (1, −1) ML and viterbidecoding for reproducing the next generation MD 1 and the nextgeneration MD2.

In the recording and/or reproducing apparatus 11, a disc 90 loadedthereon is rotationally driven by the spindle motor 21 in accordancewith the CLV system or the ZCAV system. During recording and/orreproduction, laser light is illuminated from the optical head 22 on thedisc 90.

The optical head 22 outputs high-level laser light for heating therecording layer on the recording track to the Curie temperature duringrecording, while outputting laser light of a relatively low level fordetecting the data from the reflected laser light by the magnetic Kerreffect. To this end, a laser diode as laser outputting means, an opticalsystem including a polarizing beam splitter and an objective lens, and adetector for detecting the reflected light, are mounted on the opticalhead 22. The objective lens, mounted to the optical head 22, is held byfor example a biaxial mechanism for displacement in the radial directionof the disc and in a direction towards and away from the disc. Theoptical head 22 is provided with a photodetector PD for supplying areceived light signal A and a received light signal B in an enclosedoptical disc discriminating device. Since it is necessary to determinethe proceeding direction, at the time of discriminating the opticaldisc, the objective lens or the entire optical head 22 is moved at aconstant velocity from an inner rim towards an outer rim of the opticaldisc. The received light signal A and the received light signal B may bedetected at a speed sufficient to overcome the amount of movement causedby the offset.

In the present embodiment, a phase compensation plate is provided on thereadout light path of the optical head 22 in order to develop themaximum replay characteristics for the conventional Mini-Disc and thenext generation MD1 and MD2 having different physical design parameterson the medium surface. By this phase compensation plate, the bit errorrate during readout may be optimized.

A magnetic head 23 is arranged in a location facing the optical head 22with the disc 90 in-between. The magnetic head 23 applies a magneticfield, modulated by recording data, to the disc 90. Although not shown,a sled motor and a sled mechanism are provided for causing movement ofthe optical head 22 in its entirety and the magnetic head 23 along theradius of the disc. When the enclosed optical disc discriminating devicediscriminates the optical disc, the sled motor and the sled mechanismare moved from the inner rim towards the outer rim of the optical head22.

The optical disc recording and/or reproducing apparatus 11 is providedwith a recording processing system, a reproducing processing system anda servo system, in addition to the recording and/or reproducing headsystem composed of the optical head 22 and the magnetic head 23, and tothe disc rotating driving system by the spindle motor 21. As therecording processing system, there are provided a circuit unitresponsible for EFM modulation and ACIRC encoding at the time ofrecording on a conventional Mini-Disc and a circuit unit responsible forRLL (1-7) PP modulation RS-LDC encoding at the time of recording on thenext generation MD1 and the next generation MD2.

As the reproducing processing system, there are provided a sectionresponsible for demodulation as a counterpart operation for EFMmodulation, and ACIRC decoding at the time of reproducing theconventional Mini-Disc, and a circuit unit responsible for demodulation(PR (1,2,1) ML and RLL (1-7) demodulation based on data detectionemploying viterbi decoding) and for RS-LDC decoding, as a counterpartoperation for the RLL (1-7) PP modulation at the time of reproducing thenext generation MD1 and the next generation MD2.

The information detected as the reflected light of the illuminated laserlight on the disc 90 of the optical head 22 (optical current obtained ondetecting the reflected laser light by the photodetector) is routed toan RF amplifier 24. This RF amplifier 24 executes current-voltageconversion, amplification and matrix calculations on the input detectedinformation to extract the replay RF signals, tracking error signals TE,focusing error signals and the groove information (ADIP informationrecorded on the disc 90 by track wobbling) as the replay information.

In this RF amplifier 24, there are enclosed a tracking error signalcalculating unit, making up the optical disc discriminating device ofthe optical head 22, a pull-in signal calculating unit, and acomparator.

For reproducing the Mini-Disc, the replay RF signals, obtained in the RFamplifier, are processed through the comparator 25 and the PLL circuit26 by an EFM demodulating unit 27 and an ACIRC decoder 28. The replay RFsignals are turned into bi-level signals by the EFM demodulating unit 27and turned into an EFM signal string, which then is EFM demodulated,corrected for errors and deinterleaved in the ACIRC decoder 28. If thesignals are audio data, the data at this time point are ATRAC compresseddata. At this time, the Mini-Disc signal side of the selector 29 isselected and the demodulated ATRAC compressed data are output as replaydata from the disc 90 to the data buffer 30. In this case, thecompressed data is supplied to the audio processing unit, not shown.

On the other hand, in reproducing the next-generation MD 1 or thenext-generation MD2, the replay RF signals, obtained by the RFamplifier, are processed by an RLL (1-7) PP demodulating unit 35 and anRS-LDC decoder 36, via an A/D converting circuit 31, an equalizer 32, aPLL circuit 33 and a PRML circuit 34. As for the replay RF signals,replay data, as an RLL (1-7) code string, is obtained by data detectionemploying PR (1,2,1) ML and viterbi decoding, in the RLL (1-7) PPdemodulating unit 35. On this RLL (1-7) code string, RLL (1-7)demodulation processing is carried out. The resulting data is correctedfor errors and deinterleaved in the RS-LDC decoder 36.

In this case, the next generation MD1—next generation MD2 side of theselector 29 is selected, such that the demodulated data is output asreplay data from the disc 90 to the data buffer 30. The demodulated datais then supplied to a memory transfer controller, not shown.

The tracking error signals TE and the focusing error signals FE, outputfrom the RF amplifier 24, are supplied to a servo circuit 37, while thegroove information is supplied to an ADIP decoder 38.

The ADIP decoder 38 limits the bandwidth of the groove information by aband-pass filter to extract wobble components and subsequentlyeffectuates FM modulation and bi-phase demodulation to extract the ADIPaddress. If the disc is the conventional Mini-Disc or the nextgeneration MD1, the ADIP information as the absolute information on thedisc is supplied to a system controller 41 through a MD address decoder39, whereas, if the disc is the next generation MD2, the ADIPinformation is supplied to the system controller 41 through a nextgeneration MD2 address decoder 40.

The system controller 41 executes preset control processing based oneach ADIP address. The groove information is returned to the servocircuit 37 for spindle servo control.

The system controller 41 is provided with the function of a D-flipflopdiscriminating circuit making up the optical disc discriminating device.The system controller 41 discriminates the sort of the MD based on theresult of discrimination by the D-flipflop discriminating circuit.

Based on error signals, obtained on integrating the phase error betweenthe groove information and the replay clocks (PLL-based clocks at thetime of decoding), the servo circuit 37 generates spindle error signalsfor CLV servo control and for ZCAV servo control.

Based on the spindle error signals, tracking and focusing error signals,supplied form the RF amplifier 24, or track jump command or accessingcommand, from the system controller 41, the servo circuit 37 generatesvarious servo control signals, such as tracking control signals,focusing control signals, sled control signals or spindle controlsignals, and outputs these servo control signals to a motor driver 42.That is, the servo circuit 37 performs phase compensation processing,gain processing or target value setting processing, as needed, on servoerror signals or commands, to generate various servo control signals.

Based on the servo control signal, supplied from the servo circuit 37,the motor driver 42 generates preset servo driving signals. These servocontrol signals prove a sled motor driving signals (two driving signals,namely the signals for the focusing direction and those for the trackingdirection) actuating the biaxial mechanism, a sled motor driving signal,driving the sled mechanism, and a spindle motor driving signal, drivingthe spindle motor 21. By these servo driving signals, the focusingcontrol and tracking control for the disc 90 and the CAV or ZCAV controlfor the spindle motor 21 is exercised.

In discriminating the optical disc, the optical disc discriminatingdevice controls the servo circuit 37 and the motor driver 42, by thesystem controller 41, to turn on the focusing of the laser light by theobjective lens of the optical head 22. The tracking servo is notapplied. The sled servo is such as to cause the optical head 22 to bemoved from the inner rim towards the outer rim at a certain velocity.

In recording on the disc 90, high density data is supplied from a memorytransfer controller, not shown, or usual ATRAC compressed data issupplied from an audio processing unit.

In recording on the conventional Mini-Disc, the selector 43 is connectedto a conventional Mini-Disc side, such that an ACIRC encoder 44 and anEFM modulating unit 45 are in operation. When the input is an audiosignal, compressed data from an audio processing unit 19 is interleavedand added by an error correction code by the ACIRC encoder 44 so as tobe then EFM modulated by the EFM modulating unit 45. The EFM modulateddata are supplied via selector 43 to a magnetic head driver 46 whichthen causes the magnetic head 23 to apply a magnetic field correspondingto the EFM modulated data to the disc 90 to record modulated data.

In recording on the next generation MD1 and on the next generation MD2,the selector 43 is connected to the next generation MD1—next generationMD2 side, such that an RS-LDC encoder 47 and the RLL (1-7) PP modulatingunit 48 are in operation. It is noted that high density data sent from amemory transfer controller 12 is interleaved and added by an errorcorrection code of the RS-LDC system, in the RS-LDC encoder 47, and RLL(1-7) modulated by the RLL (1-7) PP modulating unit 48.

The data for recording, modulated into an RLL (1-7) codestring, issupplied via selector 43 to the magnetic head driver 46, which thencauses the magnetic head 23 to apply a magnetic field corresponding tothe modulated data to the disc 90 to record the data.

A laser driver/APC 49, which causes a laser diode to emit laser light inreplay and in recording, described above, also effectuates so-called APC(automatic laser power control). Specifically, a detector for monitoringthe laser power, not shown, is provided within the optical head 22, witha monitor signal thereof being fed back to the laser driver/APC 49. Thislaser driver/APC 49 compares the current laser power, obtained as amonitor signal, to a preset laser power, to find an error, and causesthe error to be reflected in the laser driving signal, in order tomanage control so that the laser power output from the laser diode willbe stabilized at a setting value. It should be noted that the magnitudesof the laser power, in terms of the replay laser power and the recordinglaser power, are set in an internal register of the laser driver/APC 49by the system controller 41.

The system controller 41 controls various component parts, based oncommands from a system controller 18, such as to execute theabove-mentioned various operations, including the accessing, variousservo operations, data write or data readout operations. Meanwhile,various components parts surrounded by chain-dotted lines, shown in FIG.19, may each be constructed by a one-chip circuit.

Thus, the optical disc recording and/or reproducing apparatus 11,capable of rotationally driving the next generation MD2 in accordancewith the ZCAV system, is capable of realizing the aforementioned ZCAVsystem, by simply following up with the carrier PDIP frequency, withoutspecifically modifying the CLV system employed in the first generationMD or the next generation MD1. That is, in a given zone, the spindlemotor is being run in rotation at a constant velocity. A rotationallydriving controller does not see this in such a manner that it isrotationally driving the disc at CAV in a given zone, but rather seesthis as if the rotationally driving controller is rotationally drivingthe disc in an attempt to make the carrier frequency of the ADIPconstant.

When the optical head is moved astride the neighboring zones, the numberof revolutions of the spindle motor can be varied smoothly because thezone-to-zone speed offset is of a small value not larger than 3%.

As for zone allocation, a uniform recording unit allocation system maybe used in lieu of the constant in-zone density ratio system describedabove. This uniform recording unit allocation system is the system ofdetermining the number of zones by the number of the recording units asthe recording and/or reproducing units. For example, with the number ofzones of 23, the number of tracks/zones is 284 to 527, with the numberof clusters (number of the recording units)/zones being 504. The linedensity is 0.16 to 0.1691 μm/bit. As a result, the recording capacity is1.025 G (109). Meanwhile, the number of clusters (number of therecording units)/zones is the number excluding 4-cluster interruptionsand 4-cluster interchanges, while the recording capacity is the numberexcluding the interchanged recording units. As for the line density, thedensity ratio is 1.52 to 5.15%. The recording capacity is a valueexcluding the number of interchanged units. The system is convenient touse because the capacity per zone is determined while it may be seen howmany recording units must be passed through before the optical headreaches the neighboring zone.

The uniform track allocation system, which determines the number ofzones from the number of tracks, may also be used. For example, with thenumber of zones equal to 23, the number of tracks/number of zones is504, with the value of the number of clusters (number of recordingunits)/number of zones being 352 to 658. The line density is 0.16 to0.1663 μm/bit. Consequently, the recording capacity is 1.023 G (109).Meanwhile, the number of clusters/number of zones is a number excludingthe number of 4-cluster interruptions and the number of 4-clusterinterchanges. The density ratio, in terms of the line density ratio, is2.05 to 3.94%. The value of the recording capacity is a value excludingthe interchange recording units. In this example, accessing may befacilitated because the distance up to a given zone can be calculated interms of the number of tracks lying ahead until the zone is reached.

By way of comparison, a case of the number of zones of 23 in theconstant in-zone density ratio system is now shown by way of comparison.With the number of zones of 23, the number of tracks/number of zones is364˜660, with the value of the number of clusters (number of recordingunits)/number of zones being 338˜1158. The line density is 0.16 to0.1646 μm/bit. Consequently, the recording capacity is 1.023 G (109).The zone-to-zone speed offset (density ratio) is 2.72%. Meanwhile, thenumber of clusters/number of zones is a number excluding the number of4-cluster interruptions and the number of 4-cluster interchanges. Therecording capacity is a value excluding the number of the interchangedrecording units. This system is suited to such a case where priority isgiven to RF characteristics because it is sufficient to provide for aconstant inner radius to outer radius ratio from one zone to the next.

The logical format and the physical format of the next generation MD2are now explained.

Similarly to the next generation MD1, the next generation MD2 uses, asthe modulation system for recording data, the RLL (1-7) PP modulationsystem, suited to high density recording. Meanwhile, RLL denotes RunLength Limited, while PP denotes Parity preserve/Prohibit rmtr (repeatedminimum transition runlength). As the error correction system, an RS-LDC(Reed Solomon-Long Distance Code) with BIS (Burst Indicator Subcode)with a higher correction capability is used.

Specifically, 2048 bytes of user data, supplied from e.g. a hostapplication, and 4 bytes of EDC (Error Detection Code) appended thereto,totaling at 2052 bytes, make up one sector (data sector distinct fromthe physical sector on the disc as later explained). 32 of thesesectors, namely the sector 0 to sector 31, make up one block of 304columns by 216 rows, as shown in FIG. 20. The 2052 bytes of therespective sectors are scrambled such as to take exclusive OR (Ex-OR)with preset pseudo random numbers. 32 bytes of parity are appended toeach column of each scrambled block to form an LDC (Long Distance Code)of 304 columns by 248 rows. This LDC block is interleaved to give ablock of 152 columns by 496 rows (Interleaved LDC Block). Four sets eachof 38 columns are arrayed, with one column of the above-mentioned BISin-between, to give an array of 155 columns by 496 rows, and 2.5 bytesof the frame synchronization code (Frame Sync) are appended to a leadingposition of each column so that one column is associated with one framein order to give an array of 157.5 bytes by 496 frames, as shown in FIG.20. The respective rows of FIG. 20 are associated with 496 frames offrom Frame 10 to Frame 505 of the data area in one recording block(cluster) shown in FIG. 23 as explained later.

In the above-described data structure, data interleaving is of the blockcompletion type. This gives data redundancy of 20.50%. The datadetection system is the viterbi decoding system by PR (1,2,1) ML.

As the disc driving system, the CLV system is used, with the line speedbeing 2.4 m/sec. The standard data rate at the time of recording and/orreproduction is 4.4 MB/sec. With this system, the total recordingcapacity can be 300 MB. With the use of the RLL (1-7) PP modulationsystem, in lieu of EFM, as the modulation system, the window margin maybe 0.666 from 0.5, thus achieving a high density by a factor of 1.33.The cluster, as the minimum rewrite unit of data, is made up by 16sectors (64 kB).

Thus, by employing the RS-LDC system with BIS, employing a differentsector structure and viterbi decoding, as the recording modulatingsystem, in lieu of the CIRC system, the data efficiency can be raised to79.5%, from 53.7%, thus achieving a high density by a factor of 1.48.

By virtue of the above features, taken together, the recording capacityof the next generation MD1 can be 300 MB which is about twice that ofthe conventional Mini-Disc.

On the other hand, the next generation MD2 is a recording mediumexploiting a high density recording technique, such as DWDD (Domain WallDisplacement Detection), and has a physical format different from thatof the above-described conventional Mini-Disc or that of the nextgeneration MD1. This next generation MD2 has a track pitch of 1.25 μmand a bit length of 0.16 μm/bit and is densified along the linedirection.

Moreover, for compatibility with the conventional Mini-Disc and the nextgeneration MD1, the optical system, readout system and the servoprocessing are the same as those of the prevailing standard.Specifically, the laser wavelength λ is such that λ=780 nm, thenumerical aperture of the optical head is such that NA =0.45. Therecording system is the groove recording system, while the addressingsystem is that exploiting the ADIP. The outer shape of the casing is ofthe same standard as that of the conventional Mini-Disc and the nextgeneration MD1.

With the next generation MD2, no pre-bits are used, for achieving a highdensity, as shown in FIG. 22. Thus, in the next generation MD2, there isno PTOC area by pre-bits. In the next generation MD2, there is provided,inwardly of a recordable area, a UID area for recording the informationfor copyright protection, the information for checking data tampering orthe unique ID (UID) as a basis for other information that is not laidopen. In this UID area, recordings are made in accordance with arecording system different from the DWDD system applied to the nextgeneration MD2.

The relationship between the ADIP sector structure and the data block ofthe next generation MD1 and the next generation MD2 is now explainedwith reference to FIG. 23. In the conventional Mini-Disc (MD) system, acluster/sector structure associated with the physical address recordedas the ADIP is used. In the present specified embodiment, a clusterderived from the ADIP address is termed an [ADIP cluster] forexplanation sake, while the cluster derived from the address in the nextgeneration MD1 and the next generation MD2 is termed a [recording block]or a [next generation MD cluster].

In the next generation MD1 and the next generation MD2, a data track ishandled as a data stream recorded by a succession of clusters, asminimum address units, as shown in FIG. 23, such that one recordingblock (first generation MD cluster) is formed by 16 sectors or one-halfADIP cluster, as shown in FIG. 23.

The data structure of one recording block (first generation MD cluster)shown in FIG. 23 is made up by 512 frames, namely 10 frames of apreamble, 6 frames of a post-amble, and 496 frames of a data section.Each frame in this recording block is made up by a synchronizationsignal area, data, BIS and DSV.

Each set of 31 frames, obtained on dividing 496 frames, in which thereare recorded significant data, of the 512 frames, making up onerecording block, into 16 equal portions, is termed an address unit. Thenumber of this address unit is termed an address unit number (AUN). ThisAUN, which is a number accorded to the totality of the address units, isused for address management of recording signals.

In recording high density data, modulated in accordance with the (1-7)PP modulation system, on a conventional Mini-Disc having a physicalcluster/sector structure, described in the ADIP such as the nextgeneration MD1, a problem may be presented in which the ADIP address,inherently recorded on the disc, and an address of an actually recordeddata block, are not coincident with each other. In random accessing,which is carried out with the ADIP address as a reference, recorded datacan be read out even when access is made to a vicinity of a locationwhere there is written desired data. However, in writing data, it isnecessary to access to a correct location in order not to overwrite anderase already recorded data. It is therefor crucial to correctly graspthe access position from the next generation MD cluster/next generationMD sector associated with the ADIP address.

Thus, with the next generation MD1, a high density data cluster isgrasped by a data unit obtained on conversion of an ADIP address,recorded as a wobble on the medium surface, in accordance with a presetrule. In this case, an integer number multiples of the ADIP sector is tobe a high density data cluster. If, based on this concept, the nextgeneration MD cluster is stated in one ADIP cluster, recorded on aconventional Mini-Disc, each next generation MD cluster is formed inone-half ADIP cluster domain.

Thus, in the next generation MD1, two of the above-mentioned nextgeneration MD2 clusters are associated with one ADIP cluster as being aminimum recording unit (recording block).

In the next generation MD2, one cluster is handled as one recordingblock.

In the present specified embodiment, a 2048 byte based data block,supplied from a host application, is one logical data sector (LDS), anda set of 32 logical data sectors, recorded in the same recording block,is a logical data cluster (LDC).

With the above-described data structure, the UNM data can be recorded atan optimum timing on a recording medium, when the UMD data is to berecorded at an optional location on the recording medium. Since aninteger number of next generation MD clusters is contained in the ADIPcluster as ADIP address unit, the rule of address conversion from theADIP cluster address to the UMD data cluster address is simplified tosimplify the circuitry for conversion or the software configuration.

Although FIG. 23 shows an embodiment in which two next generation MDclusters are associated with one ADIP cluster, three or more nextgeneration MD clusters may also be arranged on one ADIP cluster. Itshould be noted that the present invention is not limited to a structurein which one next generation MD cluster is made up by 16 ADIP sectors,such that the number of the ADIP sectors that go to make up the nextgeneration MD cluster may be set depending on the difference in the datarecording density of the EFM modulation system and that of the RLL (1-7)PP modulation system, the number of sectors that go to make up the nextgeneration MD cluster or the size of one sector.

The data structure of the ADIP is hereinafter explained. FIG. 24A showsthe data structure of the ADIP of the next generation MD2, whilst FIG.24B shows the data structure of ADIP of the next generation MD1 forcomparison sake.

In the next generation MD1, there are stated a synchronization signal,the information on the cluster H information and the cluster Linformation, indicating e.g. cluster numbers in a disc, and the sectorinformation (sector) including the sector number in the cluster. Thesynchronization signal is stated with four bits, the cluster H is statedwith the upper eight bits of the address information, the cluster L isstated with lower eight bits of the address information, and the sectorinformation is stated with four bits. The CRC is appended as trailingend 14 bits. Thus, a sum total of 42 bits are recorded in a header ofeach ADIP sector.

In the next generation MD2, there are recorded four bits ofsynchronization signal data, four bits of the cluster H information,eight bits of the cluster M information, four bits of the cluster Linformation and four bits of the sector L information. BCH parity isappended as 18 trailing end bits. In the next generation MD2, 42 bits ofthe ADIP signals are recorded in a header of each ADIP sector.

In the ADIP data structure, the structures of the cluster H information,cluster M information and the cluster L information may be determinedarbitrarily. Other supplementary information can also be stated in thisstructure. For example, in the ADIP signal of the next generation MD2,shown in FIG. 25, it is possible to state the cluster information as thecluster H of the upper eight bits and the cluster L of the lower eightbits, and to state the disc control information in lieu of the cluster Lrepresented by the lower eight bits. The disc control information may beenumerated by e.g. a servo signal correction value, an upper limit valueof the replay laser power, correction coefficients for the line speed ofthe replay laser power, an upper limit value of the recording laserpower, correction coefficients for the line speed of the recording laserpower, recording magnetic sensitivity, magnetic-laser pulse phasedifference and the parity.

The replay processing and the recording processing by the disc drivingdevice for the next generation MD1 and the next generation MD2, asdiscriminated by the optical disc discriminating device, are hereinafterexplained in detail.

FIG. 26 shows the structure of a disc driving device 10 having theoptical disc recording and/or reproducing apparatus 11 as a mediumdriving unit 11. The disc driving device 10 can be connected to apersonal computer (PC) 100, and is capable of using the next generationMD1 and the next generation MD2 not only as audio data but also asexternal storage such as PC.

Referring to FIG. 26, the disc driving device 10 includes the mediumdriving unit 11, having enclosed therein the optical disc discriminatingdevice, a memory transfer controller 12, a cluster buffer memory 13, anauxiliary memory 14, a USB interfaces 15, 16, a USB HUB 17, a systemcontroller 18 and an audio processing unit 19.

The medium driving unit 11 records and/or reproduces for one 90 of avariety of discs, such as the conventional Mini-Disc, next generationMD1 or the next generation MD2. The inner structure of the mediumdriving unit 11 (optical disc recording and/or reproducing apparatus)has already been explained with reference to FIG. 19.

The memory transfer controller 12 controls transmission and reception ofreplay data from the medium driving unit 11 and recording data suppliedto the medium driving unit 11. The cluster buffer memory 13 buffers thedata read out on the high density data cluster basis from the data trackof the disc 90 by the medium driving unit 11, under control by thememory transfer controller 12. The auxiliary memory 14 memorizes avariety of the management information and the special information, suchas UTOC data, CAT data, unique ID or hash values, under control by thememory transfer controller 12.

The system controller 18 is capable of communication with the PC 100,connected thereto over the USB interface 16 and the USB HUB 17, andperforms communication control with this PC 100 to receive commands,such as write or readout requests, transmit the needed information, suchas status information, and other information, or to manage integratedcontrol of the disc driving device 10 in its entirety.

If the disc 90, for example, is loaded in the medium driving unit 11,the system controller 18 commands the medium driving unit 11 to read outthe management information from the disc 90, in order to cause themanagement information read out from the memory transfer controller 12to be stored in the auxiliary memory 14.

The system controller 18 is able to grasp the track recording state ofthe disc 90 by reading-in these management information. Moreover, byreading-in the CAT, the system controller 18 is able to grasp the highdensity data cluster structure in the data track, such that the systemcontroller 18 is able to cope with the access request for the data trackfrom the PC 100.

Based on the unique ID value or the hash value, the system controller isable to execute the disc authentication or other processing operationsor to transmit these values to the PC to cause the PC 100 to executedisc authentication processing and other processing operations.

When a readout request for a FAT sector is made from the PC 100, thesystem controller 18 gives a signal to the medium driving unit 11 to theeffect that readout of the high density data cluster including this FATsector is to be executed. The high density data thus read out is writtenby the memory transfer controller 12 in the cluster buffer memory 13.However, if data of the FAT sector has already been stored in thecluster buffer memory 13, readout by the medium driving unit 111 is notneeded.

From data of the high density data cluster, written in the clusterbuffer memory 13, the system controller 18 gives a signal for readingout the data of the FAT sector, as requested, to manage control totransmit the data of the FAT sector to the PC 100 via USB interface 15and the USB HUB 17.

When a write request for a FAT sector is made from the PC 100, thesystem controller 18 causes the medium driving unit 11 to read out thehigh density data cluster containing this FAT sector. The high densitydata cluster, thus read out, is written by the memory transfercontroller 12 in the cluster buffer memory 13. However, if the data ofthe FAT sector has already been stored in the cluster buffer memory 13,no readout by the medium driving unit 11 is needed.

The system controller 18 also causes the data of the FAT sector,transmitted from the PC 100 (recording data), to be supplied through theUSB interface 15 to the memory transfer controller 12 to executerewriting of the corresponding FAT sector data on the cluster buffermemory 13.

The system controller 18 commands the memory transfer controller 12 totransfer the data of the high density data cluster, stored in thecluster buffer memory 13 with the needed FAT sector in a rewrittenstate, to the medium driving unit 11 as recording data. The mediumdriving unit 11 writes the recording data of the high density datacluster on the medium, loaded in position, as it modulates the recordingdata in accordance with the EFM modulation system if the medium is theconventional Mini-Disc or in accordance with the RLL (1-7) PP modulationsystem if the medium is the next generation MD1 or the next generationMD2.

Meanwhile, in the disc driving device 10, the aforementioned recordingand/or reproduction control is the control in recording and/orreproducing a data track. The data transfer in recording and/orreproducing the MD audio data (audio track) is via audio processing unit19.

As an inputting system, the audio processing unit 19 includes an analogspeech signal inputting unit, such as a line input circuit/microphoneinput circuit, an A/D converter and a digital audio data input unit. Theaudio processing unit 19 includes an ATRAC compression encoder/decoderand a buffer memory for compressed data. The audio processing unit 19also includes, as an output system, an analog speech signal output unit,such as a digital audio data output unit, a D/A converter or a lineoutput circuit/headphone unit.

It is when the digital audio data (or the analog speech signal) issupplied to the audio processing unit 19 that an audio track is recordedon the disc 90. The input linear PCM digital audio data, or the linearPCM digital audio data supplied in the form of an analog speech signaland subsequently converted by the A/D converter, is ATRAC compressionencoded and stored in the buffer memory. The audio data then is read outfrom the buffer memory at a predetermined timing (data unitcorresponding to the ADIP cluster) so as to be transferred to the mediumdriving unit 11.

The medium driving unit 11 modulates the transferred compressed data inaccordance with the first modulation system, EFM modulation system orthe RLL (1-7) PP modulation system, to write the modulated data as audiotrack on the disc 90.

In reproducing the audio track from the disc 90, the medium driving unit11 demodulates the replay data to the state of the ATRAC compressed datato transfer the demodulated data to the audio processing unit 19. Thisaudio processing unit 19 performs ATRAC compression decoding on the datato turn the data into linear PCM audio data which is then output at adigital audio data output unit. Or the audio processing unit convertsthe data into analog speech signals which are then output to a lineoutput/headphone output.

It should be noted that the structure shown in FIG. 26 is merelyillustrative. For example, if the disc driving device 10 is connected tothe PC 100 so as to be used as an external storage device adapted forrecording and/or reproducing only data tracks, the audio processing unit19 is not needed. On the other hand, if recording and/or reproduction ofaudio signals is the principal target, it is preferable that there isprovided the audio processing unit 19 and further there are provided anoperating unit and a display unit as a user interface. For connection tothe PC 100, not only the USB but also the so-called IEEE1394 interfacepursuant to the provision as provided for by the IEEE (The Institute ofElectrical and Electronics Engineers, Inc.) or the general-purposeconnection interface may be used.

In accessing to a data area, a command for recording and/or reproducingdata in terms of a [logical sector] (referred to below as FAT sector) asa unit is issued from the external PC 100 through the USB interface 16to the system controller 18 of the disc driving device 10. To the PC100, it appears as if the data cluster is divided in terms of 2048 bytesas a unit and is supervised in accordance with the FAT file system inthe increasing order of the USN. On the other hand, the minimum rewriteunit of the data track in the disc 90 is the next generation MD cluster,having the size of 65,536 bytes, and the LCN is given to this nextgeneration MD cluster.

The size of the data sector, referenced by the FAT, is smaller than thatof the next generation MD cluster. It is therefore necessary for thedisc driving device 10 to convert the user sector, referenced by theFAT, into a physical ADIP address, and to convert read/write, in termsof the data sector, referenced by the FAT, into read/write in terms ofthe next generation MD cluster based read and write, using the buffermemory 13.

FIG. 27 shows the processing in the system controller 18 in the discdriving device 10 in case a request for readout of a certain FAT sectorfrom the PC 100.

On receipt of a readout command for reading out the FAT sector #n fromthe PC 100 via USB interface 16, the system controller 18 performs theprocessing of finding the next generation MD cluster number containingthe FAT sector of the specified FAT sector number #n.

The provisional next generation MD cluster number id determined. Sincethe size of the next generation MD cluster is 65536 bytes and the sizeof the FAT sector is 2048 bytes, there are 32 FAT sectors in the firstgeneration MD cluster. Thus, the FAT sector number (n) divided by aninteger 32, with the remainder being truncated (u0), represents theprovisional next generation MD cluster number.

The system controller then references the disc information, read-in fromthe disc 90 into the auxiliary memory 14, to find the number of the nextgeneration MD cluster ux other than the clusters for data recording.This number is the number of the next generation MD clusters of a securearea.

Among the next generation MD clusters within the data track, there is acluster that is not laid open as being a data recordable/reproduciblearea. Thus, the number of clusters not laid open ux is found based onthe disc information previously read into the auxiliary memory. Thenumber of clusters not laid open ux is then summed to the cluster numberu0 of the next generation MD cluster number to give a sum u which is tobe the actual next generation MD cluster number #u.

When the next generation MD cluster number #u, including the FAT sectornumber #n, is found, the system controller 18 determines whether or notthe next generation MD cluster of the cluster number #u has already beenread out and stored in the cluster buffer memory 13. If the cluster hasnot been stored, it is read out from the disc 90.

The system controller 18 finds the ADIP address #a from the nextgeneration MD cluster number #u as read out to read out the nextgeneration MD cluster from the disc 90.

The next generation MD cluster may be recorded in plural parts on thedisc 90. For this reason, these parts need be retrieved sequentially inorder to find the actually recorded ADIP address. The number of the MDclusters of the next generation and the number of the leading nextgeneration MD cluster px, recorded in the leading part of the datatrack, are found from the disc information read out in the auxiliarymemory 14.

Since the start address/end address are recorded in the respective partsby the ADIP address, the number of the next generation MD clusters p andthe leading next generation MD cluster px may be found from the discinformation read out into the ADIP cluster address and the part length.It is then verified whether or not the next generation MD cluster of thetargeted cluster number #u is included in this part. If the cluster isnot included in the part, the next part is checked. This next part isthat part which is specified by the link information of the part whichhas thus far been of interest. In this manner, the parts stated in thedisc information are sequentially retrieved to determine the partcontaining the next generation MD cluster of interest.

When the part having recorded the next generation MD cluster of interest(#u) is found, the difference between the cluster number px of the nextgeneration MD cluster recorded in the leading end of this part thusfound and the cluster number #u of the next generation MD cluster ofinterest is found to find the offset from the leading end of the part tothe next generation MD cluster (#u) of interest.

Since two next generation MD clusters are written in this case in oneADIP cluster, the offset may be converted into the ADIP address offset fby dividing the offset by 2 (f=(u−px)/2).

However, if a fractional number of 0.5 is obtained, writing is from themid part of the cluster f. Ultimately, an offset f is added to a clusteraddress part in the start address of the part to find the ADIP address#a of the destination of recording in which to actually write the nextgeneration MD cluster #u. The above corresponds to the processing ofsetting the replay start address and the cluster length in the step Si.It is here assumed that decision as to whether the medium is theconventional Mini-Disc, the next generation MD1 or the next generationMD2 has already been finished by another particular technique.

When the ADIP address #a has been found, the system controller 18commands the medium driving unit 11 to access to the ADIP address #a.The medium driving unit 11 then accesses the ADIP address #a, undercontrol by the system controller 41.

In a step S2, the system controller 18 awaits the access completion. Onaccess completion, the system controller 18 awaits the optical head 22reaching the targeted replay start address. If, in a step S4, the systemcontroller has ascertained that the replay start address has beenreached, the system controller commands the medium driving unit 11 tostart reading out one cluster of data of the next generation MD cluster.

Responsive thereto, the medium driving unit 11 commences to read outdata from the disc 90, under control by the system controller 41. Theread-out data are output by a replay system of the optical head 22, RFamplifier 24, RLL (1-7) PP demodulating unit 35 and the RS-LDC decoder36 and thence routed to the memory transfer controller 12.

In a step S6, the system controller 18 verifies whether or notsynchronization with respect to the disc 90 has been in good order. Ifthe synchronization with respect to the disc 90 is not in good order, asignal indicating the purport of occurrence of a data readout error isgenerated in a step S7. If, in a step S8, it is determined that readoutis to be performed again, the step as from step S2 is repeated.

When one cluster data has been acquired, the system controller 18 in astep S10 commences correcting the acquired data for errors. If, in astep S11, there is an error in the acquired data, the system controller18 reverts to a step S7 to generate a signal indicating that a datareadout error has occurred. If there is no error in the acquired data,it is verified in a step S12 whether or not a preset cluster has beenacquired. When the preset cluster has been acquired, the sequence ofprocessing operations is terminated. The system controller 18 awaits thereadout operation by the medium driving unit 11 to store data read outand supplied to the memory transfer controller 12 in the cluster buffermemory 13. When the preset cluster has not been acquired, the process asfrom the step S6 is repeated.

One cluster data of the next generation MD cluster, read into thecluster buffer memory 13, includes plural FAT sectors. Thus, from theseFAT sectors, the storage location of data of the requested FAT sector isfound and data of one FAT sector (2048 bytes) are sent out from the USBinterface 15 to the external PC 100. Specifically, the system controller18 finds, from the requested FAT sector number #n, a byte offset #bwithin the next generation MD cluster containing this sector. The systemcontroller causes data for one FAT sector (2048 bytes), from thelocation of the byte offset #b in the cluster buffer memory 13, totransfer the so read-out data via USB interface 15 to the PC 100.

By the above processing, the next generation MD sector may be read outand transferred responsive to a readout request for one FAT sector fromthe PC 100.

Referring to FIG. 28, the processing by the system controller 18 in thedisc driving device 10 in case a write request for a given FAT sector ismade from the PC 100 is now explained.

On receipt of a write command for the FAT sector #n via USB interface 16from the PC 100, the system controller 18 finds the next generation MDcluster number containing the FAT sector of the FAT sector number #n,specified as described above.

When the next generation MD cluster number #u, including the FAT sectornumber #n, is found, the system controller 18 verifies whether or notthe next generation MD cluster of the cluster number #n thus found hasalready been read out from the disc 90 and stored in the cluster buffermemory 13. If the cluster has not been stored, the processing forreading out the next generation MD cluster of the cluster number #u isperformed. That is, the system controller 18 commands the medium drivingunit 11 to read out the next generation MD cluster of the cluster number#u to store the so read out next generation MD cluster in the clusterbuffer memory 13.

Thus, from the FAT sector number #n, requested for writing, the systemcontroller 18 finds the byte offset #b in the next generation MD clustercontaining the sector. The system controller 18 then receives 2048 bytedata, as write data for the FAT sector #n, transferred from the PC 100,via USB interface 15, and causes the data corresponding to one FATsector data (2048 bytes) from the position of the byte offset #b in thecluster buffer memory 13.

In this manner, only the FAT sector (#n), specified by the PC 100, amongthe data of the next generation MD cluster (#u), stored in the clusterbuffer memory 13, is in a rewritten state. The system controller 18 thenprepares for writing the next generation MD cluster (#u), stored in thecluster buffer memory 13, on the disc 90. The above is the process in astep S21 for making preparations for the recording data. It is againassumed that decision as to the medium type has already been completedby another particular technique.

In the next step S22, the system controller 18 sets, from the number #uof the next generation MD cluster to be written, an ADIP address #a ofthe recording start position. When the ADIP address #a has been found,the system controller 18 commands the medium driving unit 11 to accessto the ADIP address #a. This causes the medium driving unit 11 to accessto the ADIP address #a, under control by the system controller 41.

If it is ascertained in a step S23 that the access has come to a close,the system controller 18 waits until the optical head 22 reaches thereplay start address of interest. If it is ascertained in a step S25that the data encode address has been reached, the system controller 18in a step S26 commands the memory transfer controller 12 to starttransfer to the medium driving unit 11 of data of the next generation MDcluster (#u) stored in the cluster buffer memory 13.

When it is ascertained in a step S27 that a recording start address hasbeen reached, the system controller 18 in a step S28 commands the mediumdriving unit 11 to start writing data of the next generation MD clusteron the disc 90. Responsive thereto, the medium driving unit 11 startswriting data on the disc 90, under control by the system controller 41.That is, the data transferred from the memory transfer controller 12 isrecorded by a recording system composed of the RS-LDC encoder 47, RLL(1-7) PP modulating unit 48, magnetic head driver 46, magnetic head 23and the optical head 22.

The system controller 18 in a step S29 verifies whether or notsynchronization with respect to the disc 90 is in good order. Ifsynchronization with respect to the disc 90 is out of order, the systemcontroller 18 in a step S30 generates a signal to the effect that a datareadout error has occurred. If it is determined in a step S31 thatreadout is again executed, the process as from the step S2 is repeated.

When one cluster data has been acquired, the system controller 18 in astep S32 checks whether or not a preset cluster has been acquired. Whena preset cluster has been acquired, the sequence of operations isterminated.

By the above-mentioned processing, writing the FAT sector data on thedisc 90 responsive to the write request for one FAT sector from the PC100 may be achieved. That is, the FAT sector based writing is executedas rewriting of the next generation MD cluster unit, insofar as the disc90 is concerned.

Although the present invention has so far been elucidated with referenceto certain preferred embodiments, it is apparent that these embodimentsare merely illustrative and the present invention can be modified by theskilled artisan by correction or substitution of the embodiments withinthe scope not departing from the purport of the invention.

INDUSTRIAL APPLICABILITY

According to the present invention, the inphase-outphase matching may beachieved on an average, by equating the number of carrier waves fromzone to zone, whereby low frequency components may be prohibited frombeing superposed on WPP signals. When the optical disc is used for arecording and/or reproducing apparatus, reproduction is by CAV in agiven zone. In recording and/or reproduction, the spindle motor iscontrolled as conventionally, whereby the disc is in rotation as it isrun by CLV.

1. A disc-shaped recording medium, comprising: a signal recordingsurface, the signal recording surface being split into a plurality ofzones concentrically, wherein a track is formed spirally orconcentrically, such that, in each zone, the number of waves of a wobbleis the same from one turn of the track to the next and wherein at leastone dummy track incapable of recording and/or reproduction is providedin the neighborhood of a boundary between two given neighboring zones.2. The disc-shaped recording medium according to claim 1 wherein, ineach zone, the wobble of a given turn of the track is in phase with thewobble of a neighboring turn of the track or a given track is in phasewith the wobble of a neighboring track.
 3. The disc-shaped recordingmedium according to claim 1 wherein at least two turns of a dummy trackor at least two dummy tracks incapable of recording and/or reproductionare provided in the neighborhood of a boundary between two givenneighboring zones.
 4. The disc-shaped recording medium according toclaim 1 wherein data are recorded in terms of an optional block as aunit and wherein two block units in a vicinity of an innermost rim ofeach zone and two block units in a vicinity of an outermost rim of eachzone are formed as dummy tracks incapable of recording and/orreproduction.